Inverters

[Q]

You are plugging a 2000 watt inverter into a 12V outlet?

An inverter that size needs to be connected to the battery with short/fat cables. Smaller wire or any sort of plug in receptical will cause resistance, voltage drop, and chance of fire if not properly fused.

Q

[kartvines]

Yes I did just to test it, worked ok once my truck engine was started. Question, does the cooling fan run all of the time like it does on my 400 watts, i assume it would.

[Q]

Some inverters run the fan all the time, some run it when it heats up, others run it whenever there is a substantial load but before it heats up. I don't know how that one is designed but I prefer the type that doesn't run the fan all the time.

Q

[Woody]

I use a 1000 watt inveter and the fan only comes on when hot and it cycles dependant on the load it will cycle on and off. Mostly on, I use it only when I need it though. They are nice to have, but, in one year I'll bet I turned it on a bunch of times to see the LED's light up. Only used twice when camping for power for short periods of time

[GregJ]

kartvines, my 1000w inverter is connected to the batteries with 2/0 cable (though #0 would work). For 2000w you'll likely pull 200 amps peak at 12v. My book says you want 4/0... that's about the size of your thumb.

Your right, a dashboard plug probably isn't enough to let it start up. You may want to look at your battery too. I'm not sure you can get 200 amps through most 12v batteries and certainly not for very long. I'm using 2, L-16s at the "cabin" (350 a/h @ 6v, and 120 lbs each).

BTW: Exeltech makes a nice 250w (& 150w) true sine inverters ( I know, it's $300) but that seems like it might fit a tear. Enough for CF lights, TV, DVD and small power tools. If you want air conditioning IMHO you need a hook-up or a generator.

[kartvines]

Greg

Thank you for the information

[GregJ]

Greg

Thank you for the information

Hope it helped. The info came from the manual for my Prosine-1000 (lists the larger ones as well). I checked a couple of other places and the numbers came out a little different but not much. With an inverter you are much better off with the heaver cable.

This is a bit simplistic: Volts * Amps = Watts . Using 12v the current get real high real fast. At 12v if you divide the watts by 10 you get a pretty good number for amps with some safety margin and surge capability. You are sleeping in there, and fires are so annoying.

[Arne]

I'm checking my wiring in my t/d to be sure it is okay. With all switches off, I still get a small spark when I put the main fuse in. The only thing it can be is the inverter. There is a green power light with is lit all the time, and the inverter is hardwired into the 12v system..... and the inverter switch is off.

So, I'm thinking the inverter is using a minor amount of power even when turned off...... and it is draining my battery even when not in use.

I have noticed after a week of just sitting, when I plug in the battery tender, it takes a while for the red charge light to go off..... so, do people with inverters have an additional switch to unhook the inverter when it is not being used to completely disconnect it from the 12v source?

[Q]

All inverters that I'm aware of use a bank of capacitors on the input side. Those capacitors are not switched out of the circuit when the power switch is turned off. So.. when you put power to the input side of the inverter you'll get a spark as the capacitors charge. Once charged, the inverter shouldn't use any power, or almost no power.

My 3000 watt inverter makes a pretty scary spark when connected to 12V!

Q

[Arne]

Thank you for the explanation... I'm going to try a test, one week with inverter in line, and one week out, to see what the battery recharge time is...

Won't be real scientific, but what the heck.....

[Q]

Arne,

A real easy way to check to see if something is drawing current from the battery is to get a multimeter that reads amps and put it is series with the pos or neg battery cable. Even those cheap $3.99 digital meters sold at Harbor Freight will do the job.

Q

[Arne]

I thought about that, but was afraid I would fry my meter.... don't know how much draw they can stand before they pop.... The leads on mine on not very beefy...

[Chris C]

Arne, they'll handle 240 volts easy. Don't think you'd have any problem with 110.

[asianflava]

I thought about that, but was afraid I would fry my meter.... don't know how much draw they can stand before they pop.... The leads on mine on not very beefy...

They are usually fused. You can check inside the battery compartment to see if there are any fuses. The annoying part is finding the replacement fuses.

[GeorgeTelford]

Hi

Just spotted this thread, so I am answering all posts on the way through.

1. Invertors draw .7 Amp minimum even when doing nothing

2. A 700w Microwave will use around 1050w Input to run, this isnt start up Wattage, 700w Refers to the cooking output only it needs 1050 to make 700w Output

3. Running the microwave on low will not help, it cycles on and off, therefore its still running 1050w most of the time.


Here is something I wrote way back to help people understand Microwaves and Invertors
http://s7.invisionfree.com/UKSB/index.php?showtopic=29

Never ever use a suicide lead, even if you think you will always remember to plug the off side in first before it becomes live you (or someone else) may forget one day. This is especially dangerous because;

GFCI these will not work with an Invertor because invertors have no earth, this means there is no earth for any current to leak to ergo GFCI as no reference and will not operate, this means that the only way to get a shock is a direct short between the live and return pins (which on a suicide lead exposes both) Direct shorts are the most unlikely kind of electrocution.

You can run a mains fridge via invertor, but you need a fair few batteries to wild camp (I have 10 X110 Ah batteries) Its also ok if you always intend to use shore power, you can power via invertor on way (which is powered by engine alternator)

Running computers via Modified sine wave, many people (over here) including me have done it no problems at all and not suffered any adverse effects.

There are only a few things that wont work on Modified

1. Washing machines they have thyristor control
2. Power tools with thyristor speed control, try it it will either work or not
3. Electric toothbrush chargers, do not try it ever it will destroy the charger
4. Dual sets ie TV/DVD and TV/VCR many have these have thyristor's in the twin power supplies internally BUT do try it many also work no problems at all.

Always use big thick cables and site your invertor close to the batteries. voltage drop is not really a problem out the mains side, but its a serious issue on the12v Side.

In the last few posts its been mentioned about the drain when not in use, I guarantee its .7 or above. but I have noticed several people reccomending using a meter and some confusion about what actually to measure 240v? etc, If you have no idea do not go messing with a meter and battery, scrapping a meter is the least of your worries, serious injury could result.

Just for the record you need to measure ampage, most modern meters will check up to 10 Amps without a shunt. if you dont get it do not try.

Have fun